AB0977 CHANGES IN ASDAS AND SYMPTOMS OF ANXIETY AND DEPRESSION IN AXIAL SPONDYLOARTHRITIS: LATENT TRAJECTORY ANALYSIS
Authors: S. S. Zhao, C. Webers, E. Nikiphorou, D. Van der Heijde, J. Braun, U. Kiltz, S. Ramiro, A. Boonen
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Disease-assessment in axial spondyloarthritis (axSpA) includes subjective measures that do not necessarily reflect inflammatory processes in the spine and joints. Mental health comorbidities such as anxiety and depression can be secondary to inflammatory and non-inflammatory processes. There may be subgroups that respond differently to axSpA treatment, for example, discordance in these indices whereby disease activity improves but not mental health. Understanding such potential subgroups and their characteristics can support individualised care. <h3>Objectives</h3> To apply data-driven approaches to longitudinal disease activity (ASDAS) and Hospital Anxiety and Depression Scale (HADS) subscores for anxiety (HADS-A) and depression (HADS-D) to identify potential groups with discordant trajectories. <h3>Methods</h3> This was an ancillary analysis of the data collected for the Assessment of SpondyloArthritis international Society Health Index (ASAS HI) Validation Study. We included individuals who fulfilled ASAS criteria for axSpA and required a therapeutic change (initiation of NSAID, csDMARDs or TNFi) due to active disease. Those with diagnosis of peripheral SpA were excluded. Participants were assessed at baseline and one follow-up. Group-based trajectory models were used to group individuals based on shared trajectories of ASDAS, HADS-A and HADS-D. These three dependent variables were standardised (scale 0 to 10), then included in linear models with a time indicator (baseline or follow-up) as the independent variable. We selected the optimum number of groups through statistical fit. Individuals were assigned to the group with the highest posterior probability of membership. Patient and disease characteristics were compared across groups. <h3>Results</h3> Of 206 participants (mean age 37 years, 65% male), 73 (35%) started NSAIDs, 23 (11%) csDMARD and 109 (53%) TNFi (Table 1). The optimum number of trajectory groups was 4 (Figure 1). Three indices changed concordantly regardless of the number of latent groups. Group descriptions are relative: Group (G) 1 (54%) started with low scores for all three indices, G2 (34%) moderate, and G3 (5%) high. Mean improvements in ASDAS were numerically similar across these groups. G4 (7%) had the greatest improvement across all three indices. Initiated therapy differed with G3 and 4 more frequently starting TNFi. <h3>Conclusion</h3> Results of this study show that ASDAS and symptoms of anxiety and depression are closely related and change concordantly with treatment, and suggest that reported musculoskeletal and mental health symptoms influence each other. There were no clear differences in patient or disease characteristics across these groups except for age. Whether axSpA patients benefit from knowing that mental health symptoms generally improve jointly with disease activity when starting treatment remains to be shown. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.